PERST and CPPE Signals (Robin, Woodpecker)

Robin and Woodpecker allows to use of Express Cards. Those cards are using the signals PERST# and CPPE#.
By the standard, PERST# which is the Express Card reset, is low as long CPPE# is high. As soon as a Express Card is plugged in, the cards pulls CPPE# low, and after a fixed delay of 100ms, the PERST# signal rises high. This behavior resets the Express Card properly.
On Robin Z5xx and Woodpecker Z5xx, Hot Plug on PCIe is not supported. Therefore the signal CPPE# is obsolete. In order to support Express Cards as well, the PERST# signal is held low after CB_RESET# for 100ms.